High solids detergent compositions



United States Patent F HIGH SOLIDS DETERGENT COMPOSITIONS David Aelony, Minneapolis, Minn, assignor to General Mills, Inc., a corporation of Delaware No Drawing. Application June 17, 1953, Serial No. 362,421

6 Claims. (Cl. 260-534) The present invention relates to high solids detergent compositions composed essentially of compounds having the following formula:

RNHCHzCHzCOOM water, organic bases and aqueous alkali. In the hydrolysis I with the aqueous alkali, however, the Isbell patent recognizes that there are distinct difiiculties in trying to produce a detergent composition of high concentration. The Isbell patent discloses the hydrolysis of the ester, either with a fairly dilute solution of sodium hydroxide or by adding solid sodium hydroxide to a heterogeneous mixture of water and the ester. In each instance, however, it is found necessary to add further quantities of water during the hydrolysis in order to produce a satisfactory product. The patent further recognizes that heat is required for hydrolysis, and that when it is attempted to heat a viscous mixture, overheating is likely, resulting in apartial discoloration of the product. By this method it was possible to obtain compositions having a concentration of 2530%. The patent further recognizes the extreme difiiculty involved in attempting to produce a solid product from this hydrolyzate in view of the intensive foaming characteristics of the product.

It has now been discovered that it is possible to hydrolyze esters of the type disclosed in the Isbell patent by employing concentrated solutions of aqueous alkali such that the product which is obtained is essentially solid and may contain from 60l00% of the detergent solids.

It is, therefore, an object of the present invention to provide a novel process of hydrolyzing fatty'amineacrylate condensation esters in the presence of concentrated alkali to produce detergent compositions of very high solids content.

It is another object of the present invention to provide a novel product resulting from the above process.

The process of condensing the acrylic ester with the primary fatty amines is disclosed in the Isbell patent. The present invention is applicable to the condensation products obtained from condensing primary amines containing from 8-22 carbon atoms with acrylate esters of such lower aliphatic alcohols as methyl, ethyl, propyl and butyl. The invention is applicable to the hydrolysis of these esters with sodium and potassium hydroxide. The invention is based on the discovery that these esters saponify almost 2,814,643 Patented Nov. 26, 1957 immediately when brought into contact with a concentrated hot aqueous solution of the above alkali. The products which are obtained can contain from 60100% of the active solids in a form ready for shipment. These materials have a pH range of 10.5-11.0 in a 0.1% concentration in water. It is thus possible to ship a solid detergent instead of a dilute aqueous solution. Furthermore, it is possible to readily prepare liquid detergent products containing from 40-60% active solids dissolved in mixtures of water and alcohol. These may be used as dishwashing compounds, shampoos, liquid soaps and the like. Furthermore, these salts can be converted to the N-alkyl beta amino propionic acids by suspending the salt in 99% isopropanol, adding a calculated amount of hydrochloric acid, filtering out the precipitated salts and evaporating the isopropanol solution. These N-alkyl beta amino propionic acids are useful in the preparation of amine salts of said acid.

In the hydrolysis it is preferred to employ a concentration of the aqueous alkali of from 15% by weight up to the percentage represented by a saturated solution of the alkali at approximately 100 C. In the case of sodium hydroxide this is approximately 77%; in the case of potassium hydroxide, 64%. A concentration of approximately 50% has been found particularly desirable.

It is apparent that the hydrolysis may be conducted either with a simple solution of the alkali in water, or if desired, the solution of the alkali may be in a mixture of water and a water-soluble alcohol such as methyl, ethyl, isopropyl or propyl. Nevertheless, the invention does contemplate the use of the concentrated alkalis referred to above. The employment of the alcohol during the hydrolysis may facilitate the solution of the product after hydrolysis.

An elevatedtemperature is preferred to initiate the reaction. This may be accomplished by heating one or both of the reactants separately before admixing or by heating the mixture. Temperatures in the range of 50", C.-l20 C. may be used. Generally, the preferred range is -10090. I

The amount of; alkali preferred is a quantity substantially equivalentto the ester used. An excess may be used where a higher pH is desired in the product for specific uses.

Example I Distilled tallow amine (265.3, g.) which analyzed as follows:

Amine number 212.8 Iodine value 39.9 Percent primary amine 99.0 Percent secondaryamine 0.2

was heated to 100 C. at 10 mm. absolute pressure and was cooled to 60 C. Methyl acrylate (94 g.) was added over a period of one hour. Agitation at 60 C. was continued for 5 hours. Vacuum was thenapplied and the mixture was heated to 100 C. at 50m. The yield was 353 g. of product.

325 g. of this product were added to a hot solution of 38 g. of sodium hydroxide in 38 cc. of water. The reaction mixture was heated for one hour in a steam bath with occasional stirring. The product was composed of the sodium salt in a 95% concentration. I

Example 2 Distilled coco amines (208 g.) which analyzed as fol- Percent secondary amine 0 Iodine value 5.0

was heated to 100 C. at mm., cooled to 60 C. and 94 g. of methyl acrylate was added over a 1 minute period. Agitation at 60 C. was continued for 4 hours, after which a vacuum was applied and the temperature was raised to 100 C. at 50 The yield was 294 g.

The ester (279 g.) was added to a boiling solution of 40 g. ofsodium hydroxide and 40 g. of water. The flask was rinsed with 20 cc. methanol and the washings were added to the reaction mixture. Samples were taken out immediately after the reaction subsided (sample A); then the beaker was placed on a steam bath and samples were taken out after minutes (sample B); 30 minutes (sample C); 1 hour (sample D); 2 hours (sample B). These samples were dried overnight in a vacuum oven at 80 C. They were then made into 0.1% solutions and the pHs were adjusted to 10.0 and Ross-Miles foam tests were run with the following results.

Immediate After 5 min.

Example 3 Distilled coco amine characterized in Example 2 (212 g.) was heated to 100 C. at 10 mm., cooled to 60 C. at which point 94 g. of methyl acrylate were added over a period of 1 minute. Agitation at 60 C. was conducted for 4 hours. A vacuum was then applied and the temperature raised to 100 C. at 10 mm. The yield was 299 g.

The hot ester was poured into a boiling solution of 41 g. of sodium hydroxide and 41 cc. of water. The flask was rinsed with a little methanol and the washings were added to the reaction mixture. The mixture was kept on the steam bath for 2 hours, at which time it had a solids content of 90.5%. The Ross-Miles foam test indicated a foam height of 167 mm. In a Launderorneter a value of 30.0 was obtained. This was somewhat higher (107.7%) than the value obtained with a commonly used commercial detergent of the fatty alcohol sulfate type.

Example 4 The methyl ester of Example 3 (887 g.) was heated to 100 C. and was mixed with a boiling solution of 114 g. of sodium hydroxide in 114 g. of water. A very rapid reaction took place. When the evolution of methanol slackened, the reaction mixture was kept on the steam bath for one hour with occasional agitation. The product had a solids content of 87%. The Ross-Miles foam test indicated a foam height of 161 mm. After 5 minutes the foam height was 158 mm. A wetting time of 27.2 seconds was observed by the canvas disc test.

Example 5 The methyl ester of Example 2 (192 g.) was mixed with a solution of 28 g. sodium hydroxide and 28 cc. water. When the temperature of the reaction mixture was 55 C. 50 cc. of methanol was added and a vigorous reaction ensued, bringing the temperature to 75 C. The product was evaporated on a steam bath until it contained 80% solids. It gave a Ross-Miles foam test of 190 mm. with no deterioration of foam height after 5 minutes.

Example 6 72 g. of the ester obtained by the condensation of methyl acrylate with distilled coco amines from which Cs to C10 amines had been removed, were hydrolyzed by means of 10 g. NaOl-I dissolved in 40 cc. H2O. The reaction mixture was heated on the steam bath for one hour at which time the product contained 77% solids. When this reaction is carried out in a closed vessel and no evaporation is permitted, approximately 60% solids are present in the product.

By employing an even less concentrated alkali such as 15% aqueous alkali and permitting evaporation of Water and/ or alcohol during the hydrolysis, products containing at least 60% sol-ids can also be obtained.

I claim as my invention:

1. Process of hydrolyzing a compound having the formula:

RNHCH2CH2COOR in which R is an aliphatic hydrocarbon group containing from 8-22 carbon atoms and R is a lower alkyl group which comprises heating said compound with an aqueous solution of an alkali metal hydroxide having a concentration of at least 15% until hydrolysis is substantially complete.

2. Process of hydrolyzing a compound having the formula:

RNHCH2CH2COOR in which R is an aliphatic hydrocarbon group containing from 8-22 carbon atoms and R is a lower alkyl group which comprises adding the compound to a heated aqueous solution of an alkali metal hydroxide having a concentration of a least 15 agitating the mixture and allowing the hydrolysis to be to substantial completion.

3. Process of hydrolyzing a compound having the formula:

RNHCH2CH2COOR in which R is an aliphatic hydrocarbon group containing from 8-22 carbon atoms and R is a lower alkyl group which comprises adding the compound to a heated aqueous solution of an alkali metal hydroxide having a concentration of approximately 50%, agitating the mixture and allowing the hydrolysis to go to substantial completion.

4. Process of hydrolyzing a compound having the fromula:

RNHCHzCHzCOOCI-Is in which R is an aliphatic hydrocarbon group containing from 8-22 carbon atoms which comprises adding the compound to a heated aqueous solution of sodium hydroxide having a concentration of approximately 50%, agitating the mixture and allowing the hydrolysis to go to substantial completion.

5. Process of hydrolyzing a compound having the formula:

RNHCHiCH2COOR in which R is an aliphatic hydrocarbon group containing from 822 carbon atoms and R is a lower alkyl group which comprises heating said compound with an aqueous solution of an alkali metal hydroxide having a concentration of at least 15 and including a small quantity of a lower aliphatic alcohol until hydrolysis is substantially complete.

6. Process of hydrolyzing a compound having the formula:

RNHCH CH COOR in which R is an aliphatic hydrocarbon group containing from 8-22 carbon atoms and R is a lower alkyl group which comprises adding the compound to a heated aqueous solution of an alkali metal hydroxide having a concentration of at least 15% and including a small quantity of a lower aliphatic alcohol, agitating the mixture and allowing the hydrolysis to go to substantial completion.

(References on following page) 6 References Cited in the file of this patent 904,520 Ellis H e Nov. 24, 1908 UN STATES PATENTS 2,468,012 lsbell P 1949 158,720 Lehmann JanilZ, 1875 OTHER REFERENCES 433,119 Enrich July 29, 1890 Ralston: Fatty Acids and Their Derivatives (1948), pp. 265, 272. 

1. PROCESS OF HYDROLYZING A COMPOUND HAVING THE FORMULA: 